Fuse plug



R. B. WOLCOTT.

Jan. 9, 1923.

FUSE PLUG.

FILED ,IAN-10,192.0.

` 2 SHEETS-SHEET L.

R. B. WOLCOTT.

Jan. 9, 1923.

FUSE PLUG.

FILED JAN. 1o. 1920.

2 SHEETS-SHEET 2.

Patented Jan. 9, 1923.

UNITED STATES PATENT OFFICE.

ROBESON B. WOLCOTT, OF CLEVELAND. OHIO, ASSIGNOR OF ONE-HALF T0 JOSEPH N. BARRETT, OF CLEVELAND HEIGHTS, OHIO.

FUSE PLUG.

Application led January 10, 1920. Serial No. 350,547.

To all whom t may (2o/neem Be it known that I, RoBnsoN B. WoLoo'rr, a citizen of the United States, residing at Cleveland in the county of Cuyahoga and State of hio, have invented a certain new and useful Improvement in Fuse Plugs, of Which the following is a full, clear, concise, and exact desecription, reference being had to the accompanying drawings, forming a part of this specication.

My invention relates to fuse plugs and more particularly to a fuse plug which is adapted to fit the ordinary lamp socket which is used in house Wiring circuits. Fuse f plugs of this nature must be inexpensive and still must be strong and tire proof.

It is an object of the invention to provide a fuse plug which can be manufactured cheaply, which is strong and durable, which is neat in appearance and which can be readily inserted by any user.

There are on the market at the present day several different kinds of fuse plugs. One which is probably the mostextensively used consists of a screw threaded plug which is adapted to fit the ordinary lamp sockets. These plugs have on their interior a conductor which Will burn out and break the circuit when the current passing therethrough is in excess of the amount .intended for use in the circuit in which'the plug is inserted.

Heretofore fuse plugs of the character above set forth have been constructed ot' porcelain or other similar material upon which. porcelain was mounted the usual screw threaded she-ll which was adapted to engage the threaded socket. lt is an inlportant object of my invention to devise a. fuse plug which may be made from the standard screw threaded metallic plug which is used in the manufacture of ordinary lamp bulbs. These standard plugs may be bought in the open market and at a low price. I use the standard plug and provide therefor an inexpensive, readily attachable transparent and close fitting cover member thereby reducing theexpense of manufacture and still producing an efiicient and fire proof. fuse plug.

Other objects of the invention will be apparent from the detailed description of the device disclosed in the drawings accompanying this specification. In this specification and in the drawings l have disclosed several forms which m invention may take, whlch forms are the est known t0 me at the present time. However, it is to be understood that b this specification and the accompanying rawings I do not intend to limit myseltl to the specific constructions disclosed as modifications in these structures may be required in the manufacture thereof or may occur to those skilled in this art. The real nature and scope of the invention disclosed is to be determined from the claims appended to this specification.

The same reference characters have been used t0 designate the same parts throughout the several views of the drawings in which- Fig. 1 is a top plan View of my improved fuse plug with the cover member removed.

Fig, 2 is a. bottom plan view of the cover member, a part of said member being shown in section in order to more clearly disclose the locking grooves formed therein.

Fig. 3 is a section taken on line 3-3 of Fig. 1 but showin the cover member in position on the shelify Fig. 4 is a partial vertical section taken on line 1 -4 of Fig. 1.

y Fig. 5 is a horizontal section taken on line 5-5 of Fig. 3.

Fig. 6 is a detailed view showing how the glass supporting fingers and the locking fingers are formed on the edge of the body member.

Fig. 7 shows a slightmodification.

Fig. 8 is a vertical section taken on line 8 8 of Fig. 7.

Fig. 9 is a top plan View of a modified form of fuse plug.

Fig. 10 is a partial vertical section taken on vline 10-10 of Fig. 9.

Fig. 11 is a partialvertical section of a further modified form of the fuse plug.

Fig. 12 is a horizontal section taken on line 12-12 of Fig. 11.

Referring to the modification shown in Figs. 1 to 6, the reference numeral 13 designates the shell portion or body portion of the plug. This shell portion has a screw threaded plug portion 14 which is adapted to fit the ordinary lamp socket. The shell portion is provided with an inturned shoulder 15 at the plug end, which inturned shoulder is adapted to support the member 16 which completely closes that end of the shell. The member 16 may be made of glass, wood7 rubber, `.(utta percha or any composite material which is non-conduct ing. imbedded in or otherwise secured to the member 16 is a metallic plate 17 which has a central opening` therethrough to receive one end ot the ruse 18. The end oit the fuse is passed through the opening' in the plate 17 and is then bent over against the plate and secured to the plate by means of solder 19. The fuse 18 extends upwardly in the shell as shown in the drawings and its upper end is securely connected to the shell portion 13 preferably by means oit solder 2O as shown. The fuse 18 therefore constitutes a conductor extending` :trom the plate 17 to the shell portion 13. The parts just described are substantially the same' the corresponding parts used on an ordinary incandescent lamp bulb. The shell portion 13, member 16 and plate 17 can be purchased in the open market at 'a very small cost. The fuse 18 can be readily attached as described above. y

ln order to make a i". se plug lire proof and to Vijn-event accidents dueto over charge a cover member is necessary iter a inse plug. rlhis cover member must prevent the escape to lire and gases Vand must also be transparent so that the `user can see whether or not the fuse 18 has been burned out. My improved fuse plug` is closed by means of a cover member 21 which is shaped as shown in the drawings and whose inside diameter is sub# stantially equal to the outside ydiameter ot the upper end of the shell po "tion 1S. The

cover member will therefore tightly engage this end ot the shell portion. The cover member is provided with an inwardly turned flange 22. VPositioned beneath the flange 22 are two lugs Q3 which lugs are diametrically opposite each other will be clear from Fig. Formed in the cover member are notches i341 which notches are positioned 900 away 'from the lugs Q3 as shown. .lhe purpose ol' these notches will be later set 't'ortli Positioned within the cover member E21 is a transparent member 25 which l. prel'cr to `make ot glass but which may be ot isinterial between the slits 27 is bent inwardly at ri gbl, angles to form the linger 26 kshown in han'. 1. There are two ol these lingers will.

be clear from the drawings. The iii lt are positioned between the notches 4r when the cover member is placed upon the shell portion.

At points 900 distance from the lingers 26 slits 2T are formed in the edge of the shell portion but the slits 28 are omitted. The portion between the slits is then cut away instead ot being bent inwardly as shown in Fig. 6. lllotches 31 are therefore provided to receive the lugs 23 of the cover member. l hen the cover member is placed upon the shell portion the lugs 23 lit in the notches just described and the notches 24- are adjacent the edges of the lingers 26. Before the cover member is placed in position on the shell portion the transparent member 25 is positioned within the end ot the shell portion wherein it will rest upon the two lingers 2G. The cover member is then slipped onto the end oit the shell and pressed downwardly until the lugs 23 engage the transparent member 25. The lugs 23 and lingers 26 being; 9Go apart cooperate to hold the transparentmember in fixed position ,within the shell and prevent tilting ot the trans'iarent member. The lugs 23 prevent the ila'nge 92 :trom coming in contact with the glass 2:3 hence a space 29 is lett between the 'flange 22 and the glass Q5. il. suitable implement then may be inserted into this space beneath the flange in order to bend lingers 30 outwardly into the notches 2d as shown in Fin'. rllhe lingers BO point in opposite directions and engage the opposite sides ot the material between the notches 24h The fingers enga'ring in the notches 9A and the lugs 23 engaging inthe notches 31 prevent theI cover member from rotating on the shellportion and the fingers 30 prevent re moval of the cover member fromthe shell pound. Y'lhc product electroidis also suitable. The transparent member Q15 exposes the ruso 1S to view and the user can readily see whether or not the 'fuse-has been burned out.r y

ln the modification shown in Figs? and 8 the parts are constructed substantially described above except that 80 are formed on the shell and normally extend outwardly'as shown. The cover .mem ber Q1 is provided with `not-ches 2K1 'for `the lingers 30. `When the cover member is positioned upon the shell `portion the fingers 30 are bent inwardly toward each other. lvllhen the cover reaches the position `wherein the is 2?, el y ne the transparent menr ber the lingers 30" 'will spring outwardly iojov l fl (l again and engage the notches Q4 of' the cover member to securely lock the cover member in position on the shell.

In Figs. 9 and 10 I have shown a further modified form of my fuse plug. In this modification I provide a shell 32 which has its upper end spun outwardly to form a flange 33. At a plurality of points the flange 33 is slitted and the material between the slits is bent inwardly to provide fingers 34 which are adapted to support the transparent member 35. The fingers 34 are positioned slightly below the upper surface of the fia-ngc 33 so that the upper surface of the transparent member 35 will be flush with the upper surface ofthe fiange 33. By bending the fingers 34 inwardly notches 36 are formed in the flange 33. Three notches 36 and three fingers 34 are shown in the drawings but it will be apparent that this member may be modified at will.

Positioned beneath the flange 33 is a ring 37 made of' any suitable insulating material. Positioned on top of the flange 33 is a ring 38 of the same insulating material. At points corresponding to the notches 36 the ring 38 is provided with depressed portions 39, which depressed portions fit into the notches 36 as will be clear from Fig. l0. Rivets 4() pass through the rings 37 and 38 and hold them in fixed relation to the flange 33. lrVhen the plug is inserted into the socket the operator will turn i the plug by means of the rings 37 and 38.`

The depressed portions 39 fitting into the notches 36 prevent rotation of the rings 37 and 38 on the flange 33. The flange 33 is of slightly less diameter than the lrings 37 and 38 as will be clear from Fig. l() so that there will be no danger of the user getting any electrical shock when inserting or removing a. plug. The ring 38 is provided with an opening 4l of less diameter than the diameter of the transparent member 9.5 so that the ring 38 serves to hohl the transparent member in position upon the fingers 34.

In the modification shown in Figs. ll and l2 the shell 4Q substantially the same the shell shown in Figs. 1 to (i but on this shell there are four fingers 43 which correspond to the fingers 26 shown in Fig. 1 and there are four sets of fingers 44 which correspond to the fingers 3() shown in Fig. After the transparent member 45 is positioned upon the fingers 43 as shown in Fig. ll the cover member 46 is cast or molded upon the shell portion 42. This provides a rigid unitary structure which is easy to make and cheap to manufacture and in which there can be no danger of" the cover member becoming detached from the shell portion.

From what has been described above the construction and operation of my improved f'use plug will be apparent.

fhat I claim as new and desire to secure by United States Letters Patent is:

l. A fuse plug of the character described comprising a shell portion and a cover member provided with a recess in an inner wall, and a finger formed on said shell portion to engage in the recess of the cover member to maintain the cover member in position upon said shell portion.

2. A fuse plug of the character described comprising a shell portion, a transparent member positioned within one end of the shell portion, a cover member provided with a recess in an inner wall thereof, and a finger formed on one end of said shell portion to engage in the recess of the cover member for maintaining said cover member in position upon said transparent member.

3. A fuse plug of the character' described comprising a tubular shell portion, a finger formed on the end of said shell portion, an insulating cover member adapted to fit over and cover the end of said shell portion provided with a notch inside adapted to be engaged by said finger whereby said finger maintains the cover member )in position upon said shell portion.

4. A fuse plug comprising a tubular shell portion, inwardly turned fingers formed at one end of said shell portion back of the edge, a transparent member loosely supported upon said fingers inside the shell, an insulation cap engaging said transparent member to hold it in position upon said fingers, and outwardly projecting means formed on the edge of said shell portion for securing said insulation cap to saidvshell portion.

5. A device of the character described comprising a shell portion, notches and fingers formed on the edge of said shell portion, a cover member. lugs and notches formed 011 said cover member and a transparent member positioned upon said fingers, the parts being soy constructed that when the cover member is positioned on said shell portion. the lugs on the cover member will engage in said notches on the shell portion, and the fingers on said shell portion will engage in the notches in said cover member.

6. A. fuse plug comprising a tubular metallic shell having integral fingers turned inwardly from an edge thereof, a transparent cover resting upon the fingers inside the shell, and an integral insulation ringed cap secured over the periphery at the end of the shell engaging and holding the cover in place and insulatingly covering the entire end of the shell. l

7. A fuse plug comprising a tubular shell having integral fingers turned inwardly from an edge thereof, a transparent cover resting upon the fingers inside the shell, a flanged cap secured over the end of the shell,

lugs to close tion cap mmovably securedoverlsad end of the shell and covering the openings eft in l0 said shell at Said lugs.

In Witness whereof', I hereunto subscribe my name this 3rd day o` .Talma-ry? A. Il 1919.

oBEeoN BfWoLoTT. 

